{"id":2382,"date":"2012-10-03T21:26:05","date_gmt":"2012-10-04T02:26:05","guid":{"rendered":"https:\/\/www.bob-easton.com\/blog\/?p=2382"},"modified":"2022-10-18T13:25:44","modified_gmt":"2022-10-18T17:25:44","slug":"treadle-lathe-treadle-and-first-turning","status":"publish","type":"post","link":"https:\/\/www.bob-easton.com\/blog\/treadle-lathe-treadle-and-first-turning\/","title":{"rendered":"Treadle Lathe – Treadle and First Turning"},"content":{"rendered":"

Roger Davis is a fortune teller, and a fellow Hoosier.<\/p>\n

\"photo<\/a><\/p>\n

Roger and I met quite awhile back over on the Sawmill Creek forums<\/a> talking about, what else, old tools. Not long after I published the last entry, Roger advised that the walnut crank probably wouldn’t last long. Now, it hasn’t actually failed but it didn’t take long for a bit of wobble to develop. Roger is a fellow woodworking enthusiast who also has day-job metal working skills and the equipment for prototyping aerospace instrumentation. Roger offered to make a “bulletproof” steel crank and I took him up on the offer. I’m absolutely amazed that he offered and acted so quickly. The crank is here and already in use. THANK YOU Roger!<\/p>\n

By the way, for the spalted maple fans, be aware that there’s such a thing as spalted steel. This crank has a bit of spalting which I consider early onset patina.<\/p>\n

The Treadle Mechanism<\/h3>\n

\"photo<\/a><\/p>\n

When I was much younger and more interested in high performance automobiles, one of the things I learned about was “unsprung weight.” That’s the weight of the car in the wheels, axles and undercarriage that isn’t moderated by the suspension system. A lot of unsprung weight dampens a car’s performance. The lower the amount of unsprung weight, the better performance can be tuned. This lathe takes that approach with the treadle. I’ve seen a lot of treadle lathes that have huge heavy treadle mechanisms. It seems to me that the effort that goes into operating a heavy treadle has the same dampening effect as excessive unsprung weight in cars. I can appreciate how a heavy flywheel adds momentum, but not if it has to drag along the dead weight of a heavy treadle. The lighter treadle was part of what drew me to this design.<\/p>\n

\"photo<\/a><\/p>\n

Three lightweight parts comprise the moving components, the treadle itself, a Pittman link, and a spacer bar that keeps the treadle parallel to the center line of the lathe. All three are of oak approximately 3\/4″ by 1-1\/2″ in measure. The treadle pivots on a 1\/2″ diameter pin that’s held in the walnut block on the foot of the right leg. The pivot hole itself is 3\/4″ diameter providing enough play for easy operation. The driving end of the pedal holds another 1\/2″ diameter pin that engages the Pittman link. The bottom hole on the Pittman link is also 3\/4″ diameter, allowing for a lot of angular movement. At the top of the Pittman link is a slot that is “a whisker” larger than 1\/2″ wide, enough to ride freely on the crank’s 1\/2″ diameter drive pin. Two u-shaped oak blocks anchor the spacer bar. The anchor pins are 1\/4″ bolts fitted in 1\/4″ holes in the blocks. The pivot holes in the spacer bar are 5\/16″. Thinking these parts might need lots of wiggle room, I tried a much loser version and ended up with a lot of clunking. The tighter version runs smoothly and without any binding.<\/p>\n

As before: Il meccanismo \u00e8\u00a0molto scorrevole!<\/p>\n

First Turning – a 24 inch object<\/h3>\n

\"photo:<\/a><\/p>\n

A couple of posts back, I mentioned that the flywheel was cut round using a jig on the band saw. Well, that “round” was approximate. It wanted some truing, not a lot but enough to make me wonder about how well a belt would track. How to get it trued up? Makeshift time!<\/p>\n

Finding a “tool rest” of an appropriate height was the first challenge. What the photo shows is an alternate use for the pair of saw benches I made ages ago. Flop them over on their sides and stack them “just so,” and the result is something good for supporting a newly arrived round nosed scraper. Not having a readily available treadling apprentice, I parked a chair beside the upturned saw benches, sat down, and treadled while leaning over and holding the chisel.<\/p>\n

The wheel is now round. The drive belt won’t have to put up with a roller coaster ride. If you watch the wheel turn, you’ll see some side-to-side wobble, for which there are two responses: don’t watch, and it’s not enough to affect operation. \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"

Roger Davis is a fortune teller, and a fellow Hoosier. Roger and I met quite awhile back over on the Sawmill Creek forums talking about, what else, old tools. Not long after I published the last entry, Roger advised that the walnut crank probably wouldn’t last long. Now, it hasn’t actually failed but it didn’t […]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[19,20],"tags":[],"class_list":{"0":"post-2382","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-shopmade","7":"category-treadle-lathe","8":"entry"},"_links":{"self":[{"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/posts\/2382","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/comments?post=2382"}],"version-history":[{"count":2,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/posts\/2382\/revisions"}],"predecessor-version":[{"id":8616,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/posts\/2382\/revisions\/8616"}],"wp:attachment":[{"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/media?parent=2382"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/categories?post=2382"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bob-easton.com\/blog\/wp-json\/wp\/v2\/tags?post=2382"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}